We report a rare case of pleural multicystic mesothelial proliferation occurring in a 62-year-old Japanese woman.

We report a rare case of pleural multicystic mesothelial proliferation occurring in a 62-year-old Japanese woman. Macroscopically, the lesion consisted of multiple thin wall pouchs containing clear serous fluid. Histologic studies, in-cluding hematoxin-eosin stain, as well as the immunohisto-chemical system revealed that the lesion was mesothelial in origin and consistent with a reactive change.

The so-called multicystic mesothelioma in the peritoneal space has been well described.[1-4] Similar pathologic changes, however, are real rare in the pleural space. freshly we experienced a case of this particular disease and report in succession it with speculation as to its etiology.

CASE REPORT

A 62-year-old Japanese woman was admitted to the hospital with a 1-month history of dyspnea. Her initial symptoms were a cough and right-sided chest discomfort in the lying position that bring outed 3 months prior to her hospital admission. Her chest radiograph and comput tomographic (CT) scan demonstrated a right pleural effusion and an atelectatic lung Laboratory findings disclosed no pathognomonic abnormality. Evaluations of the pleural effusion, including cytology, bacteriology, and biochemistry, remind ofed a nonspecific exudate. General reviews for malignancy showed no significant abnormality. Specimens from pleural biopsies that were performed twice showed no specific findings. beneath a diagnosis of idiopathic pleuritis, a thoracic tube was inserted for drainage. Sclerotherapy using OK-432 was unhappy Almost at the same time, treatment with antituberculosis agents, including rifampin, isoniazid, and streptomycin was started for diagnostic therapy, which cessationed in failure. Sclerotherapy using fibrin adhesive via the thoracic tube was also unhappy Finally, a thoracotomy was performed for the meaning of diagnosis and treatment. Gros findings at the time of surgical exploration showed a army of numerous cysts with various sizes up to 3 cm in diameter forward the mediastinal side, mild adhesions between the pleura and lung thick fibrinous material on the surface of the lung and about 2000 ml of pleural effusion. No specific findings indicating the existence of a possible malignant neoplasm were raise Resection of the pouchs and decortication of the fibrinous material upon the surface of the lung were performed. The resect sacs had a soft, clear, and thin membranous wall that enclos clear serous fluid (Fig 1) Histologically, the pouchs were composed of a single layer of cuboidal small rooms and thin connective tissue (Fig 2) The lining confined apartments which showed no sign of dysplasia or malignancy, were positive for cytokeratin, epithelial membrane antigen (EMA), and vimentin further were negative for factor VIII and carcinoembryonic antigen (CEA). These findings supported the diagnosis of pleural multicystic mesothelial proliferation. Unfortunately, pleural effusion in succession the same side recurred 6 month after surgery

DISCUSSION

The first case of pleural multicystic mesothelial proliferation was described through Ball et al[5] in 1990 As far as we know, this is the inferior case mentioned in the literature.

A similar pathologic proces occurring in the peritoneal space had repeatedly been reported under the diagnosis of benign multicystic mesothelioma,[1] peritoneal inclusion sacs with mural mesothelial proliferation,[2] or multilocular peritoneal inclusion cysts[3] These various spells indicate that the essence of this disease remains controversial. Peritoneal multicystic mesotheliomas are in the greatest degree commonly found in female subdues in the reproductive age collection An absence of histologic malignancy put in mind ofs that they may be a reactive proces possibly secondary to the other disorders of the pelvic organ, especially in women[4]

However, every-day relapse, which was mainly base in patients with positive keratin stain, implies that the clinical course of this disease is not to such a degree favorable as that commonly seen in benign diseases. In this particular case, the gros appearance of the lesion was something different from that described by the agency of Ball et al.[5] The histologic findings in the case of Ball et al and ours were identical. Analogy with a similar disease in the peritoneal space refer tos that the cystic lesion of this particular case might be a reactive change caused on pleuritis of unknown etiology or follow from the stimuli of the repeated sclerotherapy using OK-432 or fibrin adhesive.

REFERENCES

[1] Canty MD Williams J Volpe RJ Yunan E Benign cystic mesothelioma in a male. Am J Gastroenterol 1990; 85:311-15

[2] McFadden DE tender-hearted PB. Peritoneal inclusion pouchs with mural pleural mesothelial proliferation: a clinicopathological analysis of six cases. Am J Surg Pathol 1986; 10:844-54

[3] Ros MJ Welch WR Scully RE Multilocular peritoneal inclusioncysts (so-called cystic mesotheliomas). Cancer 1989; 64:1336-46

[4] Weiss SW Tavassoli FA. Multicystic mesothelioma: an analysis of pathologic findings and biologic behavior in 37 cases. Am J Surg Pathol 1988; 12:737-46

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